Process of presulfuration of hydrocarbon processing catalyst and catalyst produced by the process

ABSTRACT

For the sulfuration a new or regenerated catalyst, containing a support with a base of at least one metal oxide or a metalloid, and at least one active metal, the catalyst is impregnated in the absence of hydrogen with an aqueous ammonium sulfide solution at a temperature between 0° and 50°, in the presence of at least one sulfur additive selected in the group consisting of thiodazoles, thio acids, thio amides, thiocyanates, thio esters, thiophenols, thiosemicarbazides, thioureas, mercapto alcohols of formula ##STR1## where n and m are whole numbers, R 1 , R 2 , R 3 , R 4 , identical or different, are atoms of hydrogen or alkyl, aryl, aralkyl, alkylaryl organic radicals, thiols of formula R 1  --SH where R is an organic radical, thio ethers of formula R 1  --S--R 2  where R 1  and R 2  are defined as above and the organic disulfides of formula R 1  --S--S--R 2  where R 1  and R 2  are defined as above.

BACKGROUND OF THE INVENTION

This invention relates to a process of presulfuration of a hydrocarbonprocessing catalyst. The invention is an improvement of the processdescribed in patent EP-B-153233 of the applicant.

It is often desirable to proceed to a sulfuration (generally called"presulfuration") of metals entering the composition of certaincatalysts for refining and/or hydroconversion of hydrocarbons eitherwhen these catalysts are new or at the end of the regeneration of thesecatalysts before reusing them.

A presulfuration of the new or regenerated catalysts is thus desirablefor the use of these catalysts in the refining reactions, for example,the reactions of desulfuration or hydrodesulfuration of variousgasolines, for example, gasolines of catalytic cracking or steamcracking whose sulfur content it is suitable to lower, before use,without modifying the octane number of these gasolines or by modifyingit as little as possible.

The catalyst used for this type of desulfuration or hydrodesulfurationcontains a generally nonacid support, for example, an alumina or aluminamixtures (U.S. Pat. No. 4 334 982) or any other suitable support with abase of at least one oxide of a metal, e.g., magnesia or metalloid (U.S.Pat. Nos. 4,132,632, 4,140,626), silica, silica-aluminas,silica-magnesias, fluorosilicas, boron aluminas, clays, carbons,fluroaluminas), this mixture or these mixtures of supports able to be atleast partly in amorphous form or in crystallized form (zeolites) andthe catalyst further containing 0.2 to 30% of at least one active metalof groups VI, VIII or the like selected, for example, from the groupconsisting of cobalt, molybdenum, nickel and tungsten (U.S. Pat. No.3,732,155 and 3,804,748).

A sulfuration or presulfuration of regenerated catalyst is alsodesirable in the reactions of hydrocarbon hydroreforming (reforming inparticular of a naphtha) and of aromatic hydrocarbon production("aromizing"), for example, the production of benzene, toluene andxylenes (ortho, meta or para), either from gasolines that areunsaturated or unsaturated (for example, gasolines of pyrolysis,cracking, in particular steam cracking, or catalytic reforming), or elsefrom naphthenic hydrocarbons capable of being transformed into aromatichydrocarbons by dehydrogenation.

The catalyst can contain, for example, at least one metal of the familyof platinum, i.e., a noble metal such as platinum, palladium, iridium,rhodium, ruthenium, osmium deposited on a suitable support (alumina,silica, silica-alumina, fluoroaluminas, flurosilicas, zeolite, etc... ormixtures of such supports).

A sulfuration (presulfuration) of a new or regenerated catalyst is alsosuitable, in some cases, for the partial or total catalyst sulfuration,also with a base of one of the supports already cited at least one ofthe active metals already cited, usable in reactions, hydrocarbonconversions such as the reactions of hydrogenation, dehydrogenation,alkylation, hydroalkylation, dealkylation, hydrodealkylation, steamdealkylation, isomerization and hydrodemetalization of the heavybatches.

The metals of catalysts used in refining, hydrorefining orpetrochemistry, whether they are new or regenerated, are most often inoxidized form, at times in metal form (for some metals of reformingcatalysts, in particular). Now, the metals of these catalysts, oftenbeing active only in sulfur form or at least partially sulfur form, itis therefore necessary for the refiner or the petrochemist to perform asulfuration of the catalyst before its use.

The regeneration of the catalysts is now performed increasingly by aspecialist of catalyst regeneration, at times far from the industrialunit. Now, it seems reasonable to think of restoring to the refiner aproduct ready for use, which makes possible the original and efficientprocess of the applicant described in EP.B.153233.

When the catalyst is to be subjected, from its start preferably on thesite ("in situ"), to the standard activation reaction in the presence ofhydrogen (generally above 100° C.), this process makes it possible thento proceed, thanks to the presence of hydrogen on the site, to thesulfuration at required rates, stoichiometric or nonstoichiometric, ofthe active metal or metals entering the composition of the catalyst. Theprocess consists in incorporating ammonium sulfide in the absence ofhydrogen in the porosity of the new or regenerated catalyst.

In this process, the catalyst is generally impregnated "ex situ" in theabsence of hydrogen with an aqueous ammonium sulfide solution (NH₄)₂ ata temperature between 0° and 50° C., preferably between 10° to 35° C.and, for example, at room temperature to incorporate the suitable degreeof sulfur in the porosity of the catalyst, the processing of thecatalyst then being followed by a drying of this catalyst, for example,at a temperature lower than 120° C. and preferably between 95° and 115°C. Above 120° C., it has been seen that the sulfur was partiallyeliminated from the catalyst.

One of the advantages of the process is to be able to proceed to thepresulfuration of the catalyst only in the presence of an aqueoussolution. It has been proposed by the applicant in U.S. Pat. No.4,719,195 to introduce organic polysulfides in the porosity of thecatalytic batch; now, this last method presents the drawback ofperforming the presulfuration in the presence of an organic solvent of"white spirit" type that is more difficult to eliminate than the waterat the end of the process. This process further presents the advantageof being able to use the commercial ammonium sulfide solution just as itis.

SUMMARY OF THE INVENTION

A means has now been discovered, within the scope of this invention, toimprove the presulfuration of the catalyst, a means which will bereflected in particular by a longer stability of the catalysts duringprolonged tests.

This means consists in performing the incorporation of the ammoniumsulfide in the porosity of the catalyst, in the presence of at least oneparticular sulfur additive.

By weight, advantageously 5 to 50%, preferably 10-40% and moreparticularly 15-30% of the additive or additives selected will be usedrelative to the weight of sulfur introduced in the catalyst.

The additive or additives can be added, for example, with the solutionof ammonium sulfide, either in the pure state or dissolved in a suitablesolvent, water in particular.

The role of this additive is to increase the incorporation of sulfur inthe catalyst. In a preferred method, ammonium sulfide can be introducedon the catalyst during a first impregnation. Then, during a secondimpregnation, the additive (in aqueous solution or not) can be addedalone or mixed with ammonium sulfide.

Thus, in a more particular way, and in particular when it is desired totransform into sulfides all the oxides of the promoter metals that thecatalyst contains, the process then consists:

(a) in impregnating the catalyst at a temperature between 0° and 50° C.to its impregnation volume by an aqueous ammonium sulfide solution(NH₄)₂ S (preferably, the procedure is performed between 10° and 35°C.),

(b) in drying the catalyst at a temperature less than 120° C. andpreferably between 95° to 115° C.,

(c) in impregnating again (between 0° and 50° C., preferably between 10°and 35° C.) at least a second time the catalyst to its impregnationvolume or to a smaller volume, as a function of the amount of sulfur tobe introduced in the catalyst, by a mixture of an aqueous ammoniumsulfide solution (NH₄)₂ S and an additive according to the invention,

(d) in drying the catalyst at a temperature less than 130° C. andpreferably between 90° and 120° C. and more particularly in the vicinityof 100° C.

Optionally, if necessary, for the case where large amounts of sulfur areto be preintroduced into the catalyst, other impregnations of thecatalyst will be performed with an ammonium sulfide solution and/or theadditive, each of them being followed by a drying at a temperature lessthan 120° C.

Thus, it can be necessary to perform several impregnations because thepore volume of the catalyst is not sufficient to absorb, during thefirst impregnation, the entire theoretical aqueous solution of ammoniumsulfide and/or the additive containing the amount, stoichiometric ornot, of sulfur that is proposed to introduce into the catalytic batch (acommercial ammonium sulfide solution contains at a maximum 20% by weightof sulfur and to wish then to concentrate such solutions would bereflected by the decomposition of ammonium sulfide).

The drying which follows the first ammonium disulfide impregnation ispreferably performed in a gas containing molecular oxygen and inparticular in the air.

It thus is possible to perform the invention in the presence of a sulfuradditive selected from the group consisting of thiodiazoles, thio acids,thio amides, thiocyanates, thio esters, thiophenols, thiosemicarbazidesand thioureas. By way of example, thiobenzoic acid, 2-thiocresol,3-thiocresol, 4-thiocresol, 3,3'-thiodipropionic acid,3,3'-thiodipropionitrile, 2,3,6-trimethyl thiophenol, methylthioglycolate, 4-methyl-3-thiosemicarbazide, naphthalene-2-thiol, phenylisothiocyante, 2-phenyl thiophenol, thioacetamide, thiobenzamide,2,6-dimethyl thiophenol, 3,5-dimethyl thiophenol, 2,2'-dinitrodiphenyldisulfide, 2,5-dithiobiurea, ethyl thioglycolate, 2-methoxy thiophenol,3-methoxy thiophenol, 2-methyl-5-mercapto-1,3,4-thiadiazole,amidinothiourea, 2-amino-5-ethylthio-1,3,4-thiadiazole,2-amino-5-mercapto-1,3,4-thiadiazole, 3-amino-5-mercapto-1,2,4-triazole,2-amino thiophenol, benzene-1,3-dithiol, 3-chlorothiophenol and2,5-dimercapto-1,3,4-thiadiazole (D.M.T.D.), can be cited.

But the invention can also be performed in the presence of other typesof sulfur additives. It is thus possible to cite the mercapto alcoholsof formula: ##STR2## where n and m are whole numbers, R₁, R₂, R₃, R₄,identical or different, are hydrogen atoms or alkyl, aryl, aralkyl,alkylaryl organic radicals, etc... , preferably having 1 to 20 carbonatoms per molecule; preferably 1 to 6 carbon atoms per molecule;preferably n=1-10 (for example 1-2) and m=1-10 (for example 1-2).

By way of example, 2-mercaptoethanol, 1-mercapto-2-propanol,1-mercapto-2-butanol, 3-mercapto-1-propanol, 1-mercapto-2-hexanol,2-mercaptocyclohexanol, 2-mercaptocyclopentanol,3-mercaptobicyclo-(2,2,1)-heptane-2-ol-mercapto-2-pentanol,1-mercapto-2-phenyl-2-ethanol, 3-mercapto-3-phenyl-propan-1-ol,2-mercapto-3-phenyl-propan-1-ol, thioglycerol,9-mercapto-10-hydroxyoctadecanoic acid and10-mercapto-10-hydroxyoctadecanoic acid will be cited. Moreparticularly, the compounds of formula HS--CH₂ --CH₂ OH(2-mercaptoethanol) and HS--CH₂ --C (C₆ H₅) H--OH(1-mercapto-2-phenyl-2-ethanol) will be cited.

It is possible to use, in a more general way, the thios (thioalcohols,mercaptans, thiophenols) of formula R₁ --SH where R is an organicradical, thio ethers of formula R₁ --S--R₂ organic sulfides of formulaR₁ --S--S--R₂ or else HO--R₁ --S--S--R₂ --OH.

Thus, alkylmercaptans (such as n-butyl mercaptan, n-hexylmercaptan),monothioglycols (such as monothioethylene glycol), dithioglycols, suchas dithiopropylene glycol, arylmercaptans already cited above(thiophenols) (such as thiophenol, thiocresols), dithiobenzenes (such asdithioresorcinol), heterocycles substituted by mercapto groups (such asmercaptopyridine, mercaptopyrimidine, etc...) will be cited. As anexample of thio ethers, dialkyl sulfides (such as di-n-butyl sulfides,di-tert-butyl sulfides), dihydroxyalkyl sulfides (such as thiodiethyleneglycol (S(CH₂ CH₂ OH)₂), thiodipropylene glycol, etc...), diarylsulfides (diphenyl sulfide, etc...), diaralkyl sulfides (dibenzylsulfide, etc...), alkyl ethers, thiophenols (thioanisole, etc...),cyclic thio ethers and their substituted derivatives (ethylene sulfide,thiophene, thiazole, thiopyrone, thioxanthone, thioxanehydrol,1,4-thioxane, etc..., S-alkyl ethers of heterocycles substituted bymercaptans (2-methylthio-4,6-diamino pyridimine, etc...) will be cited.

Of the families of the preceding compounds, dimethyl sulfoxide,ethylthiol ethanol, thioglycolic acid, dithioglycol and the organicdisulfides of formula, in particular, HO--R₁ --S--S--R₂ --OH orHO--(CH₂)_(x) --S--(CH₂)_(x') --S--(CH₂)_(x") --OH where R₁ and R₂ aredefined as above, where x, x' and x", identical or different, are awhole number, will be cited.

It is also possible to cite more particularly by way of another example,diethanol disulfide or 2,2-dithiobis ethanol of formula (D.E.O.D.S.)

    HO--C.sub.2 H.sub.4 --S--S--C.sub.2 H.sub.4 --OH

soluble particularly in water, glycols and polyglycols.

EXAMPLES

The tests performed have as their object to prepare an easilyprocessible catalytic batch, to reduce the investment costs to obtain aneconomically viable output, to be able to rely on the ex-situregeneration units and to provide a saving of time to the refiner whilefacilitating the reuse of the catalytic batch.

It is recalled that the basis of the sulfuration of a catalyst accordingto the process of the invention is the same as in the prior art, namelythe use of a mixture of hydrogen and hydrogen sulfide:

    MoO.sub.3 +2H.sub.2 S+H.sub.2 →MoS.sub.2 +3H.sub.2 O+Q (1)

    9CoO+8H.sub.2 S+H.sub.2 →Co.sub.9 S.sub.8 +9H.sub.2 O+Q (2)

    3NIO+2H.sub.2 S+H.sub.2 →Ni.sub.3 S.sub.2 +3H.sub.2 O+Q (3)

The principle of the process consists in charging the catalyst byammonium sulfide mixed or not with DEDS (diethanol disulfide). This iscarried out by adsorption of this compound or these compounds in theporosity of the catalyst. The catalyst thus processed is subsequentlyactivated in the reactor of the refinery by passage of hydrogen heated,for example, between 80 and 200° C. The sulfur product releases H₂ S,the sulfuration of the oxides is then performed according to the knowntechniques recalled above.

Some tests were made on a new Ketjen 165/1.5 E catalyst, calcined at550° C., new or regenerated.

EXAMPLE 1 (COMPARATIVE)

The tested sulfuration agent (or reagent) is ammonium sulfide.

The handling is performed by submerging a given amount of catalyst in anexcessive volume of the reagent. The impregnation lasts for 1 hour.

It is proposed to introduce ammonium sulfide in the new or regeneratedKetjen catalyst whose support is of alumina and which contains 15.4% byweight of molybdenum oxide MoO₃ and 4.23% by weight of cobalt oxide CoO.The object of the operation is that, subsequently, on the site wherethis catalyst will be used, a hydrogen preprocessing of the catalyst cantransform all the molybdenum oxide into molybdenum sulfide MoS₂ and allthe cobalt oxide into cobalt sulfide of formula Co₉ S₈. The pore volumeof the catalyst is 46 ml per 100 grams of dry catalyst.

It is possible to calculate the weight of sulfur (molecular weight: 32)that it is suitable to introduce in the porosity of the catalyst totransform all the molybdenum and cobalt oxides into sulfides (MoS₂ andCo₉ S₈). 15.4 g of molybdenum oxide (molecular weight of MoO₃ : 144) in100 grams of catalyst corresponds to (see reaction (1), previous page):

    15.4/144×2×32=6.844 g of sulfur in these 100 grams of catalyst.

Likewise, 4.23 g of cobalt oxide (molecular weight: 75) in 100 grams ofcatalyst corresponds to (see reaction (2), previous page):

    4.23/75×8/9×32=1.604 g of sulfur in these 100 grams of catalyst.

It is therefore necessary to incorporate in total 6.844+1.604=8.448 g ofsulfur in 100 grams of catalyst. To perform this operation, a 20%commercial aqueous solution ammonium sulfide (NH₄)₂ S (molecular weight:68) will be used; 100 ml of such a solution contains: 0.294 molecule of(NH₄)₂ S or 0.294 sulfur atom or 9.41 g of sulfur. Since it is necessaryto introduce 8.448 g of sulfur in 100 g of catalyst, it will be suitableto use 89.77 ml of said commercial solution per 100 grams of catalyst,this volume thus corresponding to about two times the pore volume of thecatalyst (46 ml per 100 g), therefore to the necessity of performinghere two successive impregnations of the catalyst.

During a first impregnation, 46 ml of the commercial ammonium sulfidesolution in introduced in the catalyst, at regular temperature. It isdried at 105° C. for about two hours, under air. A second impregnationis then performed by 46 ml of the commercial solution and it is dried at100° C. for about two hours, under nitrogen. At this stage, the catalystcontains 8.6 grams of sulfur per 100 grams of catalyst.

It was found that by performing the dryings at 150° C., the catalystcontains only 5.18% of sulfur and the catalyst contains 5.51% of sulfurby performing the dryings at 200° C.

Various conventional analyses make it possible to conclude that sulfuris present in the catalyst in the form of ammonium polysulfide.

The results obtained on catalyst Ketjen K 165/1,5E, processed by theammonium sulfide, are as follows;

loss due to ignition at 500° C. (L.O.I. at 500° C.)

before processing : 0.81%

after processing: nitrogen: 26.76%

Carbon and sulfur analysis on the impregnated catalyst.

    ______________________________________                                                              after                                                               before    processing under                                                    processing                                                                              nitrogen                                                ______________________________________                                        S %         0.38      8.76                                                    C %         0.08      0.12                                                    ______________________________________                                    

In view of these results (in particular the values of L.O.I. at 500°C.), it is possible to say that the catalyst on the average isimpregnated at 20% of the ammonium sulfide or 8.45% of sulfur by weightof dry and oxidized catalyst, which corresponds to the object sought.

The activation of the catalyst processed above is performed by making ahydrogen stream pass at 150° C. through a catalyst bed impregnated withpolysulfide (under 30 bars).

When the bed has reached 130° C., the reaction starts up and thetemperature rises to about 150° C.

The catalyst becomes black, due to the metal sulfides formed.

The analysis of the sulfur catalyst gives a sulfur value of 8.50%.

EXAMPLE 2 (ACCORDING TO THE INVENTION)

The preceding tests are repeated as indicated above. However, here,during the second impregnation, 25 ml of the commercial ammonium sulfidesolution is used and the theoretical complement necessary for thestoichiometric sulfuration of the catalyst is provided by an aqueousdiethanol disulfide solution.

At the end of the activation of the catalyst, the analysis of the sulfurcatalyst also gives 8.50% as sulfur value.

The stability of the activities is improved in particular in prolongedtests (several hundred hours in pilot units).

EXAMPLE 3 (ACCORDING TO THE INVENTION)

The procedure is performed as in example 2 by successively using otheradditives instead of D.E.O.D.S. (diethanol disulfide or 2,2-dithiobisethanol), namely:

2-mercaptoethanol, dimethyl sulfoxide ethyl thioethane, thioglycolicacid, 3-mercapto-1-propanol, dithioglycol, mercaptoacetic acid (M.A.A.)thiodiethylene glycol, dithio glycol and D.M.T.D.(2,5-dimercapto-1,3,4-thiodiazole).

Good results approximately equivalent to those obtained with theD.E.O.D.S., without, however, completely reaching the long durations oftest performed with D.E.O.D.S., are obtained.

I claim:
 1. Process of processing a new or regenerated catalyst, containing a support with a base of at least one metal oxide or a metalloid and at least one active metal, performed in the absence of hydrogen and comprising impregnating said catalyst with an aqueous ammonium sulfide solution at a temperature between 0° and 50°, in the presence of at least one sulfur additive selected in the group consisting of thiodiazoles, thio acids, thio amides, thiocyanates, thio esters, thiophenols, thiosemicarbazides, thioureas, mercapto alcohols of formula ##STR3## where n and m are whole numbers, R₁, R₂, R₃, R₄, identical or different, are atoms of hydrogen or alkyl, aryl, aralkyl, alkylaryl organic radicals, thiols of formula R₁ --SH where R is an organic radical, thio ethers of formula R₁ --S--R₂ where R₁ and R₂ are defined as above and the organic disulfides of formula R₁ --S--S--R₂ where R₁ and R₂ are defined above.
 2. Process according to claim 1 for processing a new or regenerated catalyst containing a support with a base of at least one metal oxide and a metalloid and at least one active metal, said process comprising:(a) in impregnating the catalyst at a temperature between 0° and 50° C. to its impregnation volume by an aqueous ammonium sulfide solution, (b) in drying the catalyst at a temperature less than 120° C., (c) in again impregnating at least a second time the catalyst to its impregnation volume or to a lower volume, by an aqueous ammonium sulfide solution and at least one said additive, (d) in drying the catalyst at a temperature lower than 130° C.
 3. Process according to claim 1 wherein the weight of the additive or additives used represents 5 to 50% relative to the weight of sulfur introduced in the catalyst.
 4. Process according to claim 1, where said additive is HO--C₂ H₄ --S--S--C₂ H₄ --OH.
 5. Process according to claim 2, wherein the weight of the additive or additives used represents 5 to 50% relative to the weight of sulfur introduced in the catalyst.
 6. Process according to claim 2, where said additive is HO--C₂ H₄ --S--S--C₂ H₄ --OH.
 7. Process according to claim 3, where said additive is HO--C₂ H₄ --S--S--C₂ H₄ --OH.
 8. Process according to claim 5, where said additive is HO--C₂ H₄ --S--S--C₂ H₄ --OH.
 9. A catalyst produced by a process according to claim
 1. 10. A catalyst produced by a process according to claim
 2. 11. A catalyst produced by a process according to claim
 3. 12. A catalyst produced by a process according to claim
 4. 13. A catalyst produced by a process according to claim
 5. 14. A catalyst produced by a process according to claim
 6. 15. A catalyst produced by a process according to claim
 7. 16. A catalyst produced by a process according to claim
 8. 17. A composition comprising ammonium sulfide and an additive selected form the group consisting of thiodiazoles, thio acids, thio amides, thiocyanates, thio esters, thiophenols, thiosemicarbazides, thioureas, mercapto alcohols of formula ##STR4## where n and m are whole numbers, R₁, R₂, R₃, R₄, identical or different, are atoms of hydrogen or alkyl, aryl, aralkyl, alkylaryl organic radicals, thios of formula R₁ --SH where R is an organic radical, thio ethers of formula R₁ --S--R₂ where R₁ and R₂ are defined as above and the organic disulfides of formula R₁ --S--S--R₂ where R₁ and R₂ are defined as above.
 18. A composition according to claim 17, wherein said additive is HO--C₂ H₄ --S--S--C₂ H₄ --OH. 